Single Strike Style

Ground Shatter

At 3rd level, you are exclusively accustomed to using Heavy and Two-Handed weapons and making the world know it. As a Bonus Action when you make a weapon attack with a Heavy or Two-Handed weapon, you can slam it into the ground as part of the attack. On a successful hit, the target must make a Strength Save versus your Brawl Save DC or be knocked prone. Additionally, hit or miss, the ground in a 10 ft radius around the target becomes difficult terrain for 1 minute or until cleared by another ability or magical effect.

This feature may only be used once per turn.

All in One

At 6th level, while other weapon wielders wait for an opening, you throw caution to the wind, putting everything into one devastating attack that blasts through anything in its way.

In place of the Attack action, you can take the Single Strike action, but only when attacking with a weapon that has the Heavy or Two-Handed properties. When you do so, you gain a bonus to your attack roll, and damage roll equal to half your proficiency bonus (rounded down).

On a successful hit, you gain Resolve equal to the number of attacks you would normally make during an Attack action, and your damage is calculated as though all those attacks hit. You roll the damage dice for each attack individually, and the damage is dealt in a single instance, you add your modifier once for each attack you would have done.

Executioner

At 13th level you can sense when an enemy is weak and take advantage of it. When you make a weapon attack with a Heavy or Two-Handed weapon against a creature under half of its maximum hit points and miss, you can use your reaction to reroll the attack. This feature can only be used once per round.

Additionally, if you successfully hit the creature with this rerolled attack, you deal an additional die of damage as a devastating execution strike.

Overpower

At 20th level a raised shield or protective haki means nothing in the face of your extreme might. When you use the Single Attack action, the target of your attack cannot reduce its damage by any means—this includes resistances, immunities, temporary hit points, or abilities like Uncanny Dodge or Armament Haki(UDR).

Additionally, if your attack reduces the target to zero hit points, you regain all spent Resolve.